1. Technical Field
The present disclosure relates to a catheter assembly which dwells in a blood vessel or on a skin of a patient, allowing transfusion to the patient.
2. Background Art
Generally, when transfusion is carried out to a patient, an indwelling needle is pierced (inserted) in a blood vessel of a patient so as to dwell in the blood vessel. The distal end portion of a transfusion tube and the proximal end portion of the indwelling needle exposed on the skin are connected to provide communication with the transfusion tube. Therefore, the indwelling needle is configured as a catheter assembly such that the connection with the transfusion tube can rapidly be carried out and the connected portion can easily be allowed to dwell on the skin of the patient (see, e.g., the specification of US 2010/0204648 A).
The catheter assembly disclosed in US 2010/0204648 A includes a catheter, a catheter hub which is connected to the proximal end portion of the catheter, a needle having a sharp needle tip on the distal end, and a needle hub which is connected to the proximal end portion of the needle. Further, in the inside of the catheter hub, a valve mechanism is provided, the valve mechanism being configured with a hemostasis valve which prevents outflow of blood and a plug (pusher) which penetrates a slit of the hemostasis valve.
When using the catheter assembly, the catheter and the needle are integrally pierced in the blood vessel, and then the needle is solely pulled out so as to allow the catheter to dwell in the blood vessel. In this state, the blood flows into a passage in the catheter hub in the proximal end side via the catheter. However, the hemostasis valve contained in the catheter hub prevents the outflow of the blood. Then, the plug is inserted in an opening/closing part of the hemostasis valve and the transfusion tube is connected to the proximal end side of the catheter hub, thereby allowing the transfusion line to communicate with the blood vessel of the patient.
As for the valve mechanism of the catheter assembly, as described above, it is desirable to precisely stop the blood flowing in via the catheter, as well as to allow the connection of the catheter assembly and the transfusion tube to be carried out easily and surely. That is, it is required to simultaneously satisfy both hemostasis of blood and penetrability of the plug when inserted in the hemostasis valve (including easiness, rapidity, or reliability).
However, in the valve mechanism configured with the hemostasis valve and the plug, when hemostasis is to be improved, the slit of the hemostasis valve is configured not to open easily, which reduces penetrability and makes it difficult to insert the plug. On the other hand, when penetrability is to be improved, the opening/closing part of the hemostasis valve is configured to open easily so as to allow the plug to be inserted easily, reducing hemostasis. That is, it is difficult to simultaneously satisfy both hemostasis and penetrability of the valve mechanism of the catheter assembly.
Thus, there is a need for a catheter assembly which can improve hemostasis and penetrability of the valve mechanism using a simple configuration, thereby reducing the outflow of blood from the valve mechanism as well as improving the efficiency of a connecting operation of the transfusion tube.